Reflective highway markers including glass and plastic reflectors are utilized in applications such as marking curbs and delineating travel lanes on roadways. For installation, some markers require drilling and coring a receiving hole of predetermined depth and diameter into a surface with a surrounding seat having a greater diameter than the receiving hole, for flush mounting of the marker. Moreover, these markers may be securely installed without the use of adhesives if the depth and diameters of the receiving hole are appropriately sized to the markers.
One approach to providing receiving holes for these markers is the use of drill bits that create a surrounding seat but leave a core that has to be broken away. This necessitates multiple steps and also often results in a hole with an irregular bottom surface having an incorrect depth. Consequent improper installation of the marker can result in premature failure.